Convert between Vickers (HV), Brinell (HB), Rockwell C (HRC), Rockwell B (HRB), and Mohs hardness scales. Material presets, log-scale bar, and hardness reference table.
Material hardness — resistance to indentation or scratching — is measured on several different scales depending on the application. The Vickers (HV) and Brinell (HB) tests use indentation depth, Rockwell (HRC, HRB) uses a combination of depth and load, and Mohs measures scratch resistance on a 1-10 scale. Engineers, metallurgists, and gemologists frequently need to convert between these scales.
This calculator provides approximate conversions between five major hardness scales: Vickers, Brinell, Rockwell C, Rockwell B, and Mohs. Enter a hardness value in any scale and see equivalents in all others. The log-scale hardness bar provides visual context, and presets load common material hardnesses (mild steel, hardened steel, glass, diamond) instantly.
Note that hardness conversions are inherently approximate — different scales measure different physical properties and exact conversion depends on the material. The conversions here follow standard ASTM E140 approximations valid for typical steel and metal alloys. It helps teams compare test reports faster when different suppliers use different hardness scales.
Engineers and metallurgists often receive hardness values in different scales from different labs, suppliers, and standards documents. This tool provides practical ASTM-based approximations across Vickers, Brinell, Rockwell, and Mohs so teams can compare materials quickly, communicate limits clearly, avoid manual lookup errors during specification reviews, and make faster quality decisions with shared reference values.
Approximate conversions (based on ASTM E140 for steel): HV ≈ HB × 1.05 HRC ≈ (HV - 76) / 12 (for HV > 200) HRB ≈ (HV + 114) / 3.17 Mohs ≈ (log₁₀(HV) - 0.3) / 0.3 Note: All conversions are approximate; exact values depend on material.
Result: 210 HV / ≈11.2 HRC / 102 HRB
200 HB (Brinell) converts to approximately 210 HV (Vickers). For Rockwell C, this is on the low end of the range (valid mainly above 20 HRC). This hardness is typical of medium carbon steel.
Vickers (HV): A diamond pyramid indenter pressed into the surface; hardness = load/impression area. Range: 10-10000+ HV. Used universally for metals and ceramics. Brinell (HB): A hard steel or carbide ball pressed into the surface. Range: 1-700 HB. Preferred for castings and raw materials. Rockwell C/B: Measures depth of indentation under two loads. C scale (diamond cone) for hard materials; B scale (steel ball) for softer ones.
The American Society for Testing and Materials publishes E140, the standard conversion table for metals. These tables are empirical — derived from testing the same materials on multiple scales. The conversions in this calculator follow ASTM E140 approximations.
Knife makers select steel and heat treatment to achieve specific HRC values. Gemologists use Mohs to classify gem durability. Manufacturers spec minimum hardness for wear resistance. Quality control departments verify incoming materials against purchase specifications using portable hardness testers.
No. Different hardness tests measure different properties (indentation depth, scratch resistance), so conversions are approximate. They are valid within specific material ranges, primarily carbon and alloy steels.
Vickers uses a diamond pyramid indenter with a light load (good for thin materials and hard coatings). Brinell uses a large steel ball (good for castings and forgings). For steel in the 100-400 HB range, HV ≈ HB × 1.05.
Rockwell C (HRC) is for hard materials like hardened steel (20-70 HRC). Rockwell B (HRB) is for softer materials like brass, copper, and annealed steel (0-100 HRB).
Mohs measures scratch resistance on a 1-10 scale where each mineral can scratch all those below it. It is ordinal — the difference between Mohs 9 (corundum, HV 2000) and 10 (diamond, HV 10000) is enormous.
Hardened tool steel is typically 58-65 HRC (650-830 HV). Knife blades are usually 56-62 HRC.
Only roughly — Mohs is an ordinal scale, not a ratio scale. The relationship is approximately logarithmic. For engineering work, use Vickers or Brinell directly.